Chiron, an asteroid orbiting between Saturn and Uranus, represents the wounding we sustain in life. Because Chiron was only discovered in the 1970’s, you will find a variety of opinions on the meaning of Chiron in the chart, but the most frequent interpretation is that of the "wounded healer."
In mythology, Chiron the Centaur gave up not only his life, but also his god-like immortality in order to relieve his suffering. His reward was to be placed up in the sky for eternity.
As a centaur (half human, half animal), Chiron represents overcoming our lower, animal nature in order to serve the highest forms of human service and see the Truth of the Universe.
Chiron in your chart represents ways where you suffer, as well as how you can heal your suffering. The house it falls in explains what area of life you stop yourself, and any planets it aspects tell the story about the dynamics that play into the actual outcome.
The idea is that we create our own limitations and powerlessness in life because we hold on to ideas, behaviors, and possessions that are transitory. To end your suffering, let go of the past - bad experiences were things that happenED, not things that are happenING now. If you suffer because you can't help yourself stop a bad habit, become aware that you DO have options - you choose your actions (no one "makes you" do anything), and you alone have the power to change.